Risks of
Formula
Feeding
a brief annotated bibliography
Prepared by INFAC T Canada, November 2002. Second revision July 2006.
Risks of Formula Feeding
A Brief Annotated Bibliography
W
hen breastfeeding is not exclusively practised,
infant formulas are generally used. The World
Health Organization International Code of Marketing of Breast-Milk Substitutes requires that parents
be fully informed about the health hazards of unnecessary or improper use of infant formula. This brief
annotated bibliography gives some examples from
the extensive body of research documenting the importance of breastfeeding and in turn the associated
risks of formula feeding.
The World Health Oranization
Recommends
For Infants
and Children
1 Increased risk of asthma
2 Increased risk of allergy
3 Reduced cognitive
development
4 Increased risk of acute
respiratory disease
5 Increased altered occlusion
6 Increased risk for infection from
contaminated formula
7 Increased risk of nutrient deficiencies
The World Health Organization recommends exclusive
breastfeeding for the first six months of life, the
introduction of local, nutrient rich complementary
foods thereafter with continued breastfeeding to
two years of age or beyond.
(World Health Assembly Resolution 54.2, 2001)
8 Increased risk of childhood cancers
9 Increased risk of chronic diseases
10 Increased risk of diabetes
11 Increased risk of
cardiovascular disease
12 Increased risk of obesity
13 Increased risk of
gastrointestinal infections
14 Increased risk of mortality
15 Increased risk of otitis media
and ear infections
16 Increased risk of side effects of
environmental contaminants
For Mothers
1 Increased risk of breast cancer
2 Increased risk of overweight
3 Increased risk of ovarian cancer
and endometrial cancer
4 Increased risk of osteoporosis
5 Reduced natural child spacing
6 Increased risk of rheumatoid arthritis
7 Increased stress and anxiety
2
8 Increased risk of maternal diabetes
R ISK S OF FO R MUL A FE E D I NG
For Infants and Children
1 Increased risk of asthma
four-day food records and breastmilk samples were collected at
the infants’ age of one month.
Results showed that maternal intake of vitamin C in her diet
but not as a supplement determined the concentration of vitamin
C in breastmilk. A higher concentration of vitamin C in breastmilk
was associated with a reduced risk of atopy in the infant. Vitamin
E had no consistent relationship with atopy. Thus a maternal diet
rich in natural food sources of vitamin C during breastfeeding can
reduce the risk of atopy in high-risk infants.
■ A longitudinal prospective study of 1246 healthy infants
in Arizona, USA, aimed to determine the relationship between
breastfeeding and recurrent wheeze. The results showed that nonatopic children at the age of six years, who had not been breastfed, were three times more likely to have recurrent wheezing.
Wright AL, Holberg CJ, Taussig LM, Martinez FD. Relationship of infant
feeding to recurrent wheezing at age 6 years. Arch Pediatr Adolesc Med 149:
758-763, 1995
Hoppu U, Rinne M, Salo-Vaeaenaenen P, Lampi A-M, Piironen V, Isolauri E.
Vitamin C in breast milk may reduce the risk of atopy in the infant. Eur J of
Clin Nutr 59: 123-128, 2005
■ A study of 2184 children done by the Hospital for Sick Children
in Toronto determined that the risk of asthma and wheeze was
approximately 50 per cent higher when infants were formula-fed
compared to infants who were breastfed for nine months or longer.
3 Reduced cognitive development
■ To determine the impact of exclusive breastfeeding on cognitive development for infants born small for gestational age, this
US-based study evaluated 220 infants, using the Bayley Scale of
Infant Development at 13 months and the Wechler Preschool and
Primary Scales of Intelligence at five years. The researchers concluded that exclusively breastfed (without supplements) small for
gestational age infants had a significant advantage in cognitive
development without compromising growth.
Dell S, To T. Breastfeeding and Asthma in Young Children. Arch Pediatr
Adolesc Med 155: 1261-1265, 2001
■ Researchers in West Australia studied 2602 children to determine the development of asthma and wheeze at six years of age.
Not breastfeeding increased the risk of asthma and wheeze by 40
per cent compared to infants who were exclusively breastfed for
four months. The authors recommend exclusive breastfeeding for
at least four months to reduce the risk of asthma.
Rao MR, Hediger ML, Levine RJ, Naficy AB, Vik T. Effect of breastfeeding
on cognitive development of infants born small for gestational age. Arch
Pediatr Adolesc 156: 651-655, 2002
Oddy WH, Peat JK, de Klerk NH. Maternal asthma, infant feeding, and the
risk for asthma in childhood. J. Allergy Clin Immunol. 110: 65-67, 2002
■ The reviewers looked at 29 studies to evaluate the protective
effect of breastfeeding on asthma and atopy. After applying strict
criteria for assessment, 15 studies remained in the review. All 15
showed a protective effect of breastfeeding. They concluded that
the evidence is clear and consistent that not breastfeeding puts
infants at risk for asthma and atopy.
■ Breastfeeding has potentially long-term beneficial effects on
a person’s life through its influence on childhood cognitive and
educational development, concludes this UK study. Regression
analysis was used to determine that breastfeeding was significantly and positively associated with educational levels obtained
by age 26 as well as cognitive abilities at age 53 years.
Oddy WH, Peat JK. Breastfeeding, Asthma and Atopic Disease: An
Epidemiological Review of Literature. J Hum Lact 19: 250-261, 2003
Richards M, Hardy R, Wadsworth ME. Long-tern effects of breast-feeding in
a national cohort: educational attainment and midlife cognition function.
Publ Health Nutr 5: 631-635, 2002
■ USA school-aged children (439) born between 1991 and 1993
and who weighed less than 1,500 g at birth were given a variety
of cognitive tests. The very low-birth weight infants who had
never been breastfed were found to have lower test scores in overall intellectual function, verbal ability, visual-spatial and motor
skills than those who had been breastfed.
2 Increased risk of allergy
■ Children in Finland who had been breastfed the longest had
the lowest incidence of atopy, eczema, food allergy and respiratory allergy. At 17 years of age, the incidence of respiratory allergy for those who had little breastfeeding was 65 per cent and
for those who were breastfed the longest 42 per cent.
Smith MM, Durkin M, Hinton VJ, Bellinger D, Kuhn L. Influence of
breastfeeding on cognitive outcomes at age 6-8 year follow-up of very
low-birth weight infants. Am J Epidemiol 158:1075-1082, 2003
Saarinen UM, Kajosarri M. Breastfeeding as a prophylactic against atopic
disease: Prospective follow-up study until 17 years old. Lancet 346: 10651069, 1995
■ Children of socioeconomic disadvantaged Filipino mothers
were followed from birth through to middle childhood and assessed for cognitive ability at 8.5 and 11.5 years of age. After
controlling for confounding variables, children who had been
breastfed for 12 to 18 months had higher scores on the Philippines
Nonverbal Intelligence Test. The effects were even greater for lowbirth weight infants (1.6 and 9.8 points respectively). The authors
conclude that long-term breastfeeding is important after the
introduction of complementary foods, and even more so for lowbirth weight infants.
■ Infants with a maternal history of respiratory allergy or
asthma were assessed for atopic dermatitis during the first year of
life. Exclusive breastfeeding for the first three months of life was
found to have a protective effect against dermatitis.
Kerkhof M, Koopman LP, van Strien RT, et al. Risk factors for atopic
dermatitis in infants at high risk of allergy: The PIAMA study. Clin Exp
Allergy 33: 1336-1341, 2003
■ The effects of maternal dietary vitamins C and E on breastmilk
antioxidant composition to protect against the development of
atopy in infants were assessed. Mothers with atopic disease kept
Daniels M C, Adair L S. Breast-feeding influences cognitive development of
Filipino children. J Nutr. 135: 2589-2595, 2005
3
4 Increased risk of acute
respiratory disease
6 Increased risk for infection from
contaminated formula
■ Brazilian children not breastfed were 16.7 times more likely
to be diagnosed with pneumonia than children who had received
only breastmilk as infants.
■ A Belgian-based outbreak of necrotizing enterocolitis (NEC)
is traced back to infant formula contaminated with Enterobacter
sakazakii. A total of 12 infants developed NEC during the outbreak
and two infants (twin brothers) died.
Cesar JA, Victora CG, Barros FC, et al. Impact of breastfeeding on admission
for pneumonia during postneonatal period in Brazil: Nested casecontrolled study. BMJ 318: 1316-1320, 1999
Van Acker J, de Smet F, Muyldermans G, Bougatef A. Naessens A, Lauwers
S. Outbreak of necrotizing enterocolitis associated with Enterobacter
sakazakii in powdered infant formulas. J Clin Microbiol 39: 293-297, 2001
■ To determine the modifiable risk factors for acute lower respiratory infection in young children, this Indian hospital-based
study compared 201 cases to 311 controls. Breastfeeding was one
of the key modifiable risk factors for lower respiratory infection
in children under five years of age.
■ A case report from a recent US based outbreak of Enterobacter
sakazakii in a neonatal intensive care unit documents the death
of a 20-day-old infant who developed fever, tachycardia, decreased vascular profusions and seizures at 11 days. The infant
died at day 20. E. sakazakii cultures were identified from the
spinal fluid and traced to contaminated powdered infant formula
used in the NICU.
Broor S, Pandey RM, Ghosh M, Maitreyi RS, Lodha R, Singhal T, Kabra SK. Risk
factors for severe acute lower respiratory tract infection in under-five
children. Indian Pediatr 38: 1361-1369, 2001
Weir E, Powdered infant formula and fatal infection with Enterobacter
sakazakii. CMAJ 166, 2002
■ A number of sources were used to examine the relationship
between breastfeeding and risk of hospitalization for lower respiratory tract disease in healthy full-term infants with access to
adequate health facilities. Analysis of the data concluded that in
developed countries, infants who were formula-fed experienced
more than three times the severity of respiratory tract illness and
required more frequent hospitalization compared to infants who
had been breastfed exclusively for four months or more.
7 Increased risk of nutrient
deficiencies
■ Infants fed the same soy-based infant formula brand in Israel
during 2003 were hospitalized in intensive care units with severe
encephalopathy. Two died of cardiomyopathy. Analysis showed
that the thiamine level of the formula was undetectable. The
soy-based formula-fed infants admitted with symptoms indicating thiamine deficiency experienced a rapid improvement when
treated with thiamine.
Bachrach VRG, Schwarz E, Bachrach LR. Breastfeeding and the risk of
hospitalization for respiratory disease in infancy. Arch Pediatr Adolesc Med.
157: 237-243, 2003
5 Increased altered occlusion
Fattal-Valevski A, Kesler A, Seal B, Nitzan-Kaluski D, Rotstein M, Mestermen
R, Tolendano-Alhadef H, Stolovitch C, Hoffman C. Globus O, Eshel G.
Outbreak of Life-Threatening Thiamine Deficiency in Infants in Israel
Caused by a Defective Soy-Based Formula. Pediatrics 115: 223-238, 2005
■ Breastfeed for straight teeth is the message from this research
on feeding, sucking and dentition. This retrospective study of
1130 preschool children (three to five years of age) looked at the
impact of the type of feeding and non-nutritive sucking activity
on occlusion in deciduous dentition. Detailed infant feeding and
non-nutritive sucking activity history was collected by questionnaire in addition to an oral examination by a dentist.
Non-nutritive sucking activity has a substantial effect on altered occlusion, while the effect of bottle feeding is less marked.
Posterior cross-bite was more frequent in bottle-fed children and
in those with non-nutritive sucking activity. The percentage of
cross-bite was lower in breastfed children with non-nutritive
sucking activity (five per cent) than in bottle-fed children with
non-nutritive sucking activity (13 per cent). In conclusion, the
data demonstrates that non-nutritive sucking activity in the first
months of life is the main risk factor for development of altered
occlusion and open bite in deciduous dentition. Children with
non-nutritive sucking activity and who were bottle-fed had more
than double the risk of posterior cross-bite, while breastfeeding
seems to have a protective effect on development of posterior
cross-bite in deciduous dentition.
8 Increased risk of childhood cancers
■ The UK Childhood Cancer Study analyzed 3500 childhood cancer cases and the relationship to breastfeeding. Results showed a
small reduction for leukemia and for all cancers combined when
infants had “ever been breastfed.”
UK Childhood Cancer Investigators. Breastfeeding and Childhood Cancer. Br
J Cancer 85: 1685-1694, 2001
■ A case controlled study in the United Arab Emirates looked at
117 cases of acute lymphocytic leukemia and 117 controls. They
found that the breastfeeding duration of those with leukemia was
significantly shorter than the breastfeeding duration of the controls. They concluded that breastfeeding duration of six months
or longer may protect against childhood acute leukemia and lymphomas.
Bener A, Denic S, Galadari S. Longer breast-feeding and protection against
childhood leukaemia and lymphomas. Eur J Cancer 37: 234-238, 2001
Viggiano D. et al. Breast feeding, bottle feeding, and non-nutritive
sucking; effects on occlusion in deciduous dentition. Arch Dis Child 89:
1121-1123, 2004
■ Lack of breastfeeding is known to increase the risk of cancer.
This novel study found a significant level of genetic damage in infants aged nine to 12 months who were not breastfed. The authors
speculate that the genetic damage may play a role in the development of cancer in childhood or later life.
Dundaroz R, Aydin HA, Ulucan H, Baltac V, Denli M, Gokcay E. Preliminary
study on DNA in non-breastfed infants. Ped Internat 44: 127-130, 2002
4
10 Increased risk of diabetes
■ This systematic review to look at the evidence for the effect of
breastfeeding on the risk of developing childhood leukemia examined 111 studies from which they identified 32 eligible articles. Of
these they reviewed 10 and found that four had quality evidence
regarding the association between breastfeeding and leukemia.
In the two largest and highest-quality studies breastfeeding was
associated with a significant risk reduction and in one of these
studies, greater durations reflected greater protection. They note
that in the US approximately 1.4 billion dollars are spent annually
to treat childhood leukemia.
■ To determine the link between cow’s milk (and cow’s milkbased infant formula) consumption and the development of antibody response to cow’s milk protein, Italian researchers measured
the antibody response of 16 breastfed and 12 cow’s milk-fed
infants under four months of age. Cow’s milk-fed infants had elevated levels of beta-casein antibodies when compared to breastfed infants. They concluded that breastfeeding for the first four
months prevented the production of antibodies and could have a
preventive effect on the development of Type 1 diabetes.
Guise JM et al. Review of case-controlled studies related to breastfeeding
and reduced risk of childhood leukemia. Pediatrics 116: 724-731, 2005
Monetini L, Cavallo MG, Stefanini L, Ferrazzoli F, Bizzarri C, Marietti G, Curro
V, Cervoni M, Pozzilli P, IMDIAB Group. Bovine beta-casein antibodies in
breast-and bottle-fed infants: their relevance in Type 1 diabetes. Hormone
Metab Res 34: 455-459, 2002
9 Increased risk of chronic diseases
■ In this case-controlled study, 46 native Canadian Type II diabetes patients were matched with 92 controls. Pre- and postnatal
risk factors were compared. Breastfeeding was found to reduce
the risk of Type II diabetes.
■ Celiac disease may be triggered by an autoimmune response
when an infant is exposed to a food containing gluten proteins.
Ivarsson and her team of researchers looked at the breastfeeding
patterns of 627 children with celiac disease and at 1254 healthy
children to determine the effect of breastfeeding during the time
of introduction of gluten-containing foods on the outcome of the
development of celiac disease.
An astounding 40 per cent risk reduction was reported for the
development of celiac disease in children at two years of age or
younger for those who were breastfed when dietary gluten was
introduced. The effect was even more pronounced in infants who
continued to be breastfed after dietary gluten was introduced,
the authors noted.
Young TK, Martens PJ, Taback SP, Sellers EA, Dean HJ, Cheang M, Flett B.
Type 2 diabetes mellitus in children: prenatal and early infancy risk
factors among native Canadians. Arch Pediatr Adolesc Med 156: 651-655, 2002
■ Early introduction of infant formula, solids and cow’s milk are
factors shown to increase the incidence of Type I diabetes later
in life. Swedish (517) and Lithuanian (286) children aged 0 to 15
years who were diagnosed with Type I diabetes were compared to
non-diabetic controls. The results showed that exclusive breastfeeding for five months and total breastfeeding for longer than
seven or nine months are protective against diabetes.
Ivarsson, A. et al. Breast-Feeding May Protect Against Celiac Disease Am J
Clin Nutr 75:914-921, 2002
Sadauskaite-Kuehne V, Ludvigsson J, Padaiga Z, Jasinskiene E, Samuel
U. Longer breastfeeding is an independent protective factor against
development of type I diabetes mellitus in childhood. Diabet Metab Res Rev
20: 150-157, 2004
■ Inflammatory bowel disease and Crohn’s disease are chronic
gastrointestinal conditions that are more frequent for those who
are formula-fed. A meta-analysis on 17 relevant studies supports
the hypothesis that breastfeeding is associated with lower risks
of Crohn’s disease and ulcerative colitis.
■ Data was collected via questionnaires in this case-controlled study consisting of 868 diabetic Czech children and 1,466
controls. This study too confirms that the risk for type I diabetes decreases with increased duration of breastfeeding. Not
breastfeeding was associated with an increased risk – OR of 1.93.
Breastfeeding for 12 months or longer reduced the risk significantly – OR of 0.42.
Klement E, Cohen RV, Boxman V, Joseph A, Reif s. Breastfeeding and risk of
inflammatory bowel disease: a systematic review with meta-analysis. Am J
Clin Nutr 80: 1342-1352, 2004
■ To determine the effect of early infant feeding practices (i.e.
the impact of breastfeeding versus no breastfeeding; the duration
of breastfeeding; and the effect of breastfeeding while introducing gluten-containing foods) on the development of celiac disease
(CD), the authors reviewed the literature available on breastfeeding and CD.
They found that children with CD were breastfed for a significantly shorter period of time. Children being breastfed at the time
of gluten reduction had a 52 per cent reduction of risk for developing CD compared with children who were not breastfeeding at
the time of introduction.
The authors pose two potential mechanisms for the protective effect. First, that continued breastfeeding limits the actual
amounts of gluten received. Secondly, that breastfeeding protects
against intestinal infections. Infections can increase the permeability of the infant’s gut and therefore allow the passage of gluten
into the lamina propria.
Others have suggested that breastmilk IgA may reduce the immune response to ingested gluten or immune modulation may occur through specific T-cell suppressive effects.
Malcove H et al. Absence of breast-feeding is associated with the risk
of type 1 diabetes: a case-control study in a population with rapidly
increasing incidence. Eur J Pediatr 165: 114-119, 2005
11 Increased risk of cardiovascular
disease
■ To confirm links between infant nutrition and health risks in
later life, British researchers measured blood pressure at 13 to 16
years of age in 216 children who had been born prematurely. For
those who had received preterm infant formula or routine infant
formula, blood pressure was higher than for those who had received
breastmilk during infancy. The authors concluded that for children
born prematurely, breastfeeding lowers blood pressure in later life
and that this conclusion can be extended to term infants as well.
Singhal A, Cole TJ, Lucas A. Early nutrition in preterm infants and later blood
pressure: two cohorts after randomized trials. The Lancet 357: 413-419, 2001
Akobeng A K et al. Effects of breast feeding on risk of coeliac disease: a
systematic review and meta-analysis of observational studies. Arch Dis
Child 91: 39-43, 2006
■ This UK study looked at the cholesterol levels of 1500 children
aged 13 to 16 years and determined that breastfeeding may have
long term benefits for cardiovascular disease by reducing levels of
total cholesterol and low-density lipid cholesterol. The research
(continued on page 7)
5
R ISK S OF FO R MUL A FE E D I NG
For Mothers
1 Increased risk of breast cancer
■ To determine the link between breastfeeding and endometrial
cancer, this Japanese hospital-based case-control study compared
cases of women with endometrial cancer (155) with controls (96)
selected from women attending the outpatient clinic for cervical cancer screening. The women were interviewed to determine
breastfeeding practices, contraceptive usage, as well as potential
risk factors for endometrial cancer. The authors observed a greater risk of endometrial cancer for parous women who had never
breastfed, and concluded that breastfeeding reduces the risk of
endometrial cancer in Japanese women.
■ Breast-feeding decreases the risk of breast cancer in mothers
and infection, allergy, and autoimmunity in infants. The presence
of mediators of the innate immune system in human milk, including defensins, cathelicidins, and toll-like receptors (TLRs), were
extracted and analysed from the whey fractions of colostrum and
transitional and mature milk (n = 40) from normal mothers (n =
18) and from mothers with autoimmune or allergic diseases.
The authors suggest that the innate immune system in breast
milk is complex and likely provides protection for maternal breast
tissue and the developing digestive tract of newborns.
Okamura C, Tsubono Y, Ito K, Niikura H, Takano T, Nagase S, Yoshinaga K,
Terada Y, Murakami T, Sato S, Aoki D, Jobo T, Okamura K, Yaegashi N. Tohoku.
Lactation and risk of endometrial cancer in Japan: a case-control study. J
Exp Med 208: 109-115, 2006
Armogida, Sheila A.; Yannaras, Niki M.; Melton, Alton L.; Srivastava, Maya D.
Identification and quantification of innate immune system mediators in
human breast milk. Allergy and Asthma Proc 25: 297-304, 2004
■ Researchers from England evaluated a possible association
between cancer incidence and breastfeeding during infancy. This
study included nearly 4000 adults who were originally surveyed
from 1937-1939. The data included on meta-analysis showed that
the rates of breast cancer diagnosed in premenopausal women
were approximately 12 per cent lower among women who had been
breast-fed as infants.
4 Increased risk of osteoporosis
■ Longitudinal studies have suggested that both pregnancy and
lactation are associated with a bone mineral density loss of up
to five per cent, and that the loss recovers after weaning. Crosssectional studies have indicated that women with many children
and a long total period of lactation have similar or higher bone
mineral density and similar or lower fracture risk than their peers
who have not given birth and breastfed. This trend has been observational and found in cross-sectional case-control studies. The
causal relationships have yet to be determined.
Martin R, Middleton N, Gunnell D, Owen C, Smith G. Breast-Feeding and
Cancer: The Boyd Orr Cohort and a Systematic Review With Meta-Analysis.
Journal of the National Cancer Institute. 97: 1446-1457, 2005
2 Increased risk of overweight
Karlsson MK, Ahlborg HG, Karlsson C. Maternity and mineral density. Acta
Orthopaedica 76: 2-13, 2005
■ A Brazilian cohort of 405 women were followed at six and nine
months postpartum to determine the association between weight
retention and breastfeeding practices. When women who had 22
per cent body fat and breastfed for 180 days were compared with
those who had breastfed for only 30 days, each month of breastfeeding brought an average reduction of 0.44 kg in weight. In
conclusion the authors confirm the association between breastfeeding and postpartum weight and that the promotion of longer
duration can contribute to decreases in postpartum weight retention.
5 Reduced natural child spacing
■ A questionnaire was used to obtain data from Nigerian breastfeeding mothers to determine the impact of breastfeeding practices on lactational amenorrheoa. Exclusive breastfeeding was
practised by 100 per cent of the mothers on discharge. This went
down to 3.9 per cent at six months. Feeding on cue was practised
by 98.9 per cent of the mothers. By six weeks 33.8 per cent of
mothers resumed mensus and this rose to 70.2 per cent at six
months. The duration of lactational amenorrheoa was longer in
exclusively breast-feeding mothers than in those who were not.
None of the 178 mothers who participated in the survey became
pregnant.
Kac G, Benício MHDA, Velásquez-Meléndez G, Valente JG, Struchiner CJ.
Breastfeeding and postpartum weight retention in a cohort of Brazilian
women. Am J Clin Nutr 79: 487-493, 2004
3 Increased risk of ovarian cancer
and endometrial cancer
Egbuonu I, Ezechukwu CC, Chukwuka JO, Ikechebelu JI. Breast-feeding,
return of menses, sexual activity and contraceptive practices among
mothers in the first six months of lactation in Onitsha, South Eastern
Nigeria. J Obstet Gynaecol. 25: 500-503, 2005
■ Not breastfeeding has been associated with increased risk of
ovarian cancer. A large case-control Italian study of 1031 women
with epithelial ovarian cancer were compared to 2411 women admitted to the same network of hospitals for a wide spectrum of
acute non-neoplastic conditions, unrelated to known risk factors
for ovarian cancer. Results showed inverse trends in risk with
increasing duration of breastfeeding and the number of children
breastfed. Additional analyses by histologic subtypes suggested
that the protective role of breastfeeding would be larger for serious neoplasms.
6 Increased risk of rheumatoid
arthritis
■ Female reproductive and hormonal risks factors were studied
in a cohort of 121,700 women enrolled in the Nurses’ Health Study.
Breastfeeding for more than 12 months was inversely related to
the development of rheumatoid arthritis. The effect was found to
be dose related. Those who breastfed shorter had a higher risk.
Chiaffarino F, Pelucchi C, Negri E, Parazzini F, Franceschi S, Talamini R,
Montella M, Ramazzotti V, La Vecchia C. Breastfeeding and the risk of
epithelial ovarian cancer in an Italian population. Gynecol Oncol. 98: 304308, 2005
Karlson E W et al. Do breast-feeding and other reproductive factors
influence future risk of rheumatoid arthritis?: Results from the Nurses
Health Study. Arthiritis & Rheumatism 50: 3458-3467, 2004
6
7 Increased stress and anxiety
8 Increased risk of maternal diabetes
■ To find out if there is a relationship between feeding practices,
stress, and mood and levels of serum cortisol, prolactin and ACTH
(adrenocorticotrophic hormone) in mothers, the author compared the
emotional responses of 84 exclusively breastfeeding, 99 exclusively
formula-feeding and 33 non post-partum healthy control women. The
mothers’ responses were studied at four to six weeks post-partum.
Overall the breastfeeding mothers had more positive moods,
reported more positive events, and perceived less stress than formula-feeders. Breastfeeders had less depression and anger than
formula feeders and serum prolactin levels were inversely related
to stress and mood in formula-feeders.
■ Breastfeeding also reduces the mother’s risk of type II diabetes later in life. The longer the duration of breastfeeding, the
lower the incidence of diabetes, according to this Harvard based
study. The researchers studied 83,585 mothers in the Nurses’
Health Study (NHS) and 73,418 mothers in the Nurses’ Health
Study II (NHS II), and determined that each year of breastfeeding
reduced the mother’s risk of diabetes by 15 per cent.
Stuebe AM, Rich-Edwards JW, Willett WC, Duration of lactation and
incidence of type 2 diabetes. JAMA 294: 2601-2610, 2005
Groer M W. Differences between exclusive breastfeeders, formula-feeders,
and controls: a study of stress, mood and endocrine variables. Biol. Res
Nurs. 7: 106-117, 2005
while those who had breastfed exclusively for at least six months
had a 60 per cent risk reduction for becoming overweight compared to those who were formula-fed.
(continued from page 5)
suggests that early exposure to breastmilk may program fat metabolism in later life, resulting in lower blood cholesterol levels
and therefore a lower risk of cardiovascular disease.
Weyerman M et al. Duration of breastfeeding and risk of overweight in
childhood: a prospective birth cohort study from Germany. Int J Obes
advance online publication February 28, 2006
Owen GC, Whipcup PH, Odoki JA, Cook DG. Infant feeding and blood
cholesterol: a study in adolescents and systematic review. Pediatrics 110:
597-608, 2002
13 Increased risk of gastrointestinal
infections
■ A prospective study followed 7276 term UK infants for 7.5
years. Full data was available for 4763 children. At seven years of
age those not breastfed had both systolic and diastolic pressures
higher than those who had been breastfed. There was a 0.2mm
Hg reduction for each three months of breastfeeding. The authors
suggest there may be significant benefits during adulthood as a
one per cent reduction in population systolic blood pressure is
associated with a 1.5 per cent reduction in overall mortality.
■ Seven hundred and seventy-six infants from New Brunswick,
Canada, were assessed for the relationship between respiratory
and gastrointestinal illnesses and breastfeeding during the first
six months of life. Although the rates of exclusive breastfeeding were low, the results showed a significant protective effect
against total illness during the first six months of life. For those
breastfed, the incidence of gastrointestinal infections was 47 per
cent lower; the rate of respiratory disease was 34 per cent lower
than those who were not breastfed.
Martin RM, Ness AR, Gunnelle D, Emmet P, Smith GD. Does breast-feeding in
infancy lower blood pressure in childhood? Circulation 109: 1259-1266, 2004
12 Increased risk of obesity
Beaudry M, Dufour R, Marcoux S. Relationship between infant feeding and
infections during the first six months of life. J Pediatr 126: 191-197, 1995
■ To determine the impact of infant feeding on childhood obesity, this large Scottish study looked at body-mass index of 32,200
children aged 39 to 42 months. After elimination of confounding
factors, socioeconomic status, birthweight and sex, the prevalence of obesity was significantly higher in the formula-fed children, leading to the conclusion that formula feeding is associated
with an increase in childhood obesity risk.
■ A comparison between infants who received primarily breastmilk during the first 12 months of life and infants who were
exclusively formula-fed or who were breastfed for three months
or less, found that diarrheal disease was twice as high for the formula-fed infants as for those who were breastfed.
Dewey KG, Heinig MJ, Nommsen-Rivers LA. Differences in morbidity
between breast-fed and formula-fed infants. J Pediatr 126: 696-702, 1995
Armstrong, J. et al. Breastfeeding and lowering the risk of childhood
obesity. Lancet 359:2003-2004, 2002
■ Breastfeeding promotion in Belarus significantly reduced the
incidence of gastrointestinal infections by 40 per cent.
■ In order to determine factors associated with the development of overweight and obesity, 6650 German school-aged children between the ages five to 14 years of age were examined.
Breastfeeding was found to be protective against obesity. The
protective effect was greater when the infants were exclusively
breastfed.
Kramer MS, Chalmers B, Hodnett ED, et al. Promotion of Breastfeeding
Intervention Trial (PROBIT): A randomized trial in the Republic of Belarus.
JAMA 285: 413-420, 2001
14 Increased risk of mortality
Frye C, Heinrich J. Trend and predictors of overweight and obesity in East
German children. Int J of Obesity 27: 963-969, 2003
■ Active follow-up of 855 German mother and baby pairs was
used to determine the relationship between not breastfeeding and
increased risk of overweight and obesity. After a two year follow-up 8.4 per cent of children were overweight and 2.8 per cent
severely overweight: 8.9 per cent were never breastfed, while 62.3
per cent were breastfed for at least six months.
Children who were exclusively breastfed more than three
months and less than six months had a 20 per cent reduction risk,
■ Compared with exclusive breastfeeding, children who were
partially breastfed had a 4.2 times increased risk of death due
to diarrheal disease. Not breastfeeding was associated with a
14.2 times increased risk for death due to diarrheal disease in
Brazilian children.
Victora CG, Smith PG, Patrick J, et al. Infant feeding and deaths due to
diarrhea: A case-controlled study. Amer J Epidemiol 129: 1032-1041, 1989
7
reported for breastfeeding infants who were supplemented before
four months of age.
■ Infants in Bangladesh who were partially breastfed or not
breastfed had a risk of acute respiratory infection death 2.4 times
greater than exclusively breastfed infants. If children were predominantly breastfed the risk of death due to acute respiratory
infection was similar to that of exclusively breastfed children.
Duncan B, Ey J, Holberg CJ, Wright AL, Martines F, Taussig LM. Exclusive
breastfeeding for at least 4 months protects against otitis media.
Pediatrics 91: 867-872, 1993
Arifeen S, Black RE, Atbeknab G, Baqui A, Caulfield L, Becker S, Exclusive
breastfeeding reduces acute respiratory infection and diarrhea deaths
among infants in Dhaka slums. Pediatrics 108: e67, 2001
■ Between six and 12 months of age the incidence of first episodes of otitis media is greater for formula-fed infants than for
exclusively breastfed infants. For exclusively breastfed infants
the incidence increased from 25 per cent to 51 per cent compared
to a rise from 54 per cent to 76 per cent for exclusively formula
fed infants. The authors concluded that breastfeeding even for a
short period (three months) would significantly reduce the episodes of otitis media during infancy.
■ The researchers examined 1204 infants who died between 28
days and one year from causes other than congenital anomaly or
malignant tumor and 7740 children who were still alive at one
year to calculate mortality and whether or not the infant was
breastfed as well as the duration–response effects.
Children who were never breastfed had a 21 per cent greater
risk of dying in the postneonatal period than those who were
breastfed. Longer breastfeeding was associated with lower risk.
Promoting breastfeeding has the potential to save about 720 postneonatal deaths in the United States each year. In Canada this
would be about 72 deaths.
Duffy LC, Faden H, Wasielewski R, Wolf J, Krystofik D. Exclusive
breastfeeding protects against bacterial colonization and day care
exposure to otitis media. Pediatrics 100: E7, 1997
16 Increased risk of side effects of
environmental contaminants
Chen A, Rogan WJ. Breastfeeding and the risk of postneonatal death in the
United States. Pediatrics 113: 435-439, 2004
■ A Dutch study showed that at six years of age, cognitive
development is affected by prenatal exposure to polychlorinated biphenyls (PCBs) and dioxins. An adverse effect of prenatal
exposure on neurological outcome was also demonstrated in the
formula-fed group but not in the breastfed group. Despite higher
PCB exposures from breast milk, the study found at 18 months, 42
months of age, and at six years of age a beneficial effect of breastfeeding on the quality of movements, in terms of fluency, and in
cognitive development tests.
The data gives evidence that prenatal exposure to PCBs does
have subtle negative effects on neurological and cognitive development of the child up to school age. The study also gives evidence that breastfeeding counteracts the adverse developmental
effects of PCBs and dioxins.
■ This important study from Ghana was designed to evaluate
whether the timing of breastfeeding initiation and the type of
breastfeeding practiced are associated with risk of neonatal mortality. The study included 10,947 infants who survived day two
and whose mothers were visited during the neonatal period.
Breastfeeding was initiated during the first day in 71 per cent of
infants and in 98.7 per cent by day three. Breastfeeding was exclusive for 70 per cent during the neonatal period. The risk of neonatal
death was fourfold higher in infants given milk-based fluids or
solids in addition to breastmilk. There was a marked dose-response
of increasing risk of neonatal mortality with delayed breastfeeding
initiation from hour one to day seven. Initiation after day one was
associated with a 2.4-fold increase in mortality risk. The authors
conclude that 16 per cent of neonatal deaths can be prevented if all
infants are breastfed from day one and 22 per cent can be prevented
if breastfeeding is initiated during the first hour.
Boersma ER, Lanting CI. Environmental exposure to polychlorinated
biphenyls (PCBs) and dioxins. Consequences for longterm neurological and
cognitive development of the child. Adv Exp Med Biol 478:271-287, 2000
Edmond KM, Zandoh C, Quigley MA, Amenga-Etego S, Owusu-Agyei S,
Kirkwood BR. Delayed breastfeeding initiation increases risk of neonatal
mortality. Pediatrics 117: 380-386, 2006
■ Another Dutch study to determine the perinatal effects of exposure to polychlorinated biphenyls (PCBs), assessed breastfed and
formula-fed infants at nine years of age. By measuring auditory
P300 latencies (the reaction time to incoming stimuli, which are
known to be negatively impacted by PCBs) they found that those
who were formula-fed or breastfed for less than six to 16 weeks,
experienced greater latency and delayed mechanisms in the central nervous system that evaluate and process relevant stimuli. On
the other hand breastfeeding accelerates these mechanisms.
15 Increased risk of otitis media
and ear infections
■ The number of episodes of acute otitis media increased significantly with decreased duration and exclusivity of breastfeeding.
US infants who were exclusively breastfed for four months or
more had a 50 per cent reduction of episodes compared to infants
who were not breastfed. A 40 per cent reduction of episodes was
Vreugedenhill HJI, Van Zanten GA, Brocaar MP, Mulder PGH, WeisglasKuperus, N. Prenatal exposure to polychlorinated biphenols and
breastfeeding: opposing effects on auditory P300 latencies in 9-year old
Dutch children. Devlop Med & Child Neurol 46: 398-405, 2004
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INFACT Canada/IBFAN North America
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Prepared by Elisabeth Sterken, BSc MSc Nutritionist,
INFACT Canada/IBFAN North America, revised May 2006
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